Please help me to figure this out. Born into a dysfunctional family, Marty1 alters his parents 1955 timeline. In this new, functional family timeline, Marty2 is born and raised until he disappears in his timeline's Delorean. Dysfunctional family timeline's Marty1 accomplished his mission and returned to Marty2's timeline, which left Marty2 nothing to alter in 1955(since Marty1 was already in 1955 doing the things shown the film), and as far as I can tell, Marty2 isn't represented in the rest of the trilogy. Did the film series leave a gaping plot hole, or am I just confused??

  • I'm not sure. None of those answers take into account that there was nothing that needed to be altered in Marty2's 1955. Marty1 went back and "fixed" his, and since Marty2 was born and grew up in that altered timeline, Marty2 had nothing that needed fixing in his 1955. Commented Dec 16, 2014 at 8:08
  • I'm not sure either, hence no VTC - just a comment. Commented Dec 16, 2014 at 8:10
  • 2
    You're just not thinking fourth-dimensionally.
    – Ben Miller
    Commented Dec 16, 2014 at 11:59
  • 1
    Time is a Wibbly-Wobbly Timey-Wimey stuff...
    – user931
    Commented Dec 16, 2014 at 12:44
  • Although this question has been marked as a duplicate and I can't put this in an answer, there is a slight nuance from the other question that I would like to address. Specifically which left Marty2 nothing to alter in 1955. This isn't a plot hole at all - Marty never left 1985 with the intent to fix his family's problems, in fact he never intended to leave at all, his main goal was to escape the terrorists after they apparently killed Doc Brown. His actions in 1955 did not change that need.
    – user11521
    Commented Jul 29, 2015 at 3:13

2 Answers 2


You are thinking in a more quantum theory like way. That is not how Time Travel works in Back to the Future. In BttF, there is always only one timeline. If someone alters the timeline, the old timeline simply is deleted.

Marty1 and Marty2 are not two separate persons. Marty1 is the same person as the "new" Marty2, except he was not altered (he still has Marty1s memories) because he was "out of time" when the timeline was altered.

So basically Marty1s history gets replaced by Marty2s history up to the point where he leaves for 1955. But they still are the same person.

  • Well, technically they WERE two separate people for about 30 minutes, or however long it took Marty1 to run back to the mall and witness Marty2 race off in the DeLorean. After that, I assume they either merge into a single Marty (Marty1) or it's an infinite loop.
    – Omegacron
    Commented Dec 16, 2014 at 22:16
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    No, that is still the same Marty! The older one just does not remember because his memories basically overwrote the "new" memories. Commented Dec 17, 2014 at 9:31

There is something that needs 'fixing' (was going to write this as a comment, but it makes more sense as an answer) - George needs to stand up to Biff, which doesn't happen unless Marty gets involved.

If Marty doesn't get involved, Biff ends up dominating Georges life, which causes the dysfunctionality we see later on.

So Marty still needs to go back in time to ensure he has his father stand up to Biff in the car park, altering their future relationship.

  • But since Marty1 was already in 1955(and always would be until something altered his timeline) doing all of those things, Marty2 was... ?, doing what? I still think it`s a plothole. Commented Dec 16, 2014 at 9:34
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    @MajorStackings Marty2 is Marty1, completing the loop - its not a plot hole at all, it in-fact neatly wraps up the time travel theory used in BTTF in that there is only one time line you can travel up and down, and any changes affect that time line. Your "Marty2" is in-fact Marty1 going back to effect the changes on the time line - there is no separate Marty2, he just overlaps himself by returning to the future minutes before he leaves.
    – Moo
    Commented Dec 16, 2014 at 10:45
  • I'm still confused. After Marty1 changes history, his parents live entirely different lives. Marty2 would not remember his dysfunctional family at all since he was born into the functional families timeline. Commented Dec 16, 2014 at 15:47
  • @MajorStackings who said he would? Its not as if Martys time trips were planned with a goal in mind...
    – Moo
    Commented Dec 16, 2014 at 18:46
  • I thought you did when you stated Marty1 was Marty2. Unless Marty1's 1955 actions altered his 1985 timeline only after Marty2 departed, the 2 Martys had to be distinct individuals . Commented Dec 16, 2014 at 21:12

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